Delirium incidence, risk factors, and treatment in older adults receiving chemotherapy: A scoping review

e23025 Background: Older adults with cancer are at increased risk of delirium given their advanced age, multiple comorbidities and medications, prevalence of cognitive impairment, and possibly cancer treatment. Awareness of such risks and interventions to prevent or treat delirium is important to clinicians and to provide high quality care. However, there is scant published information on the risks of delirium with chemotherapy or evidence-based approaches to prevent or treat it. We performed a scoping review to summarize the available evidence. Methods: We conducted a scoping review using the framework of Arksey and O’Malley. We systematically searched peer-reviewed journal articles in English, French, and German from Medline, Embase, PsychINFO, CINAHL Plus, and Cochrane Central from inception until January 2017 to identify studies that examined delirium in patients receiving chemotherapy. We also attempted to identify any studies that reported on multivariable delirium risk prediction models and any clinical trials that examined prevention or treatment of delirium. Article titles and abstracts as well as full text articles were reviewed using Covidence software by two or more reviewers independently. Similarly, data extraction was performed by two independent reviewers. Results: A total of 21,678 titles and abstracts were screened, and 1,166 full-text articles were reviewed. Nineteen articles with varying study designs (retrospective administrative databases to clinical trials) reported on delirium using an acceptable diagnostic standard. Sample sizes varied from 15 to over 21,000. No one tumour site or treatment protocol constituted the majority of studies. The incidence of delirium ranged from 0 to 51% (mean 13.5%). The time course of delirium relative to the cycle of chemotherapy was inconsistently reported. No studies reported on risk prediction models for delirium, and no intervention studies to prevent or treat delirium were identified. An additional 109 studies reported on outcomes that could be part of the delirium syndrome but did not meet even our broad inclusion criteria (e.g. cognitive disturbance). Conclusions: Delirium may occur in over 1 in 8 older adults receiving chemotherapy, although there were substantial limitations in reported studies. This scoping review highlights the dearth of knowledge in the area, particularly for risk factors, prevention, and treatment, and emphasizes the need for high-quality studies examining these important outcomes in the oncology setting.